[Hatredcopter]

How difficult? Well, Japanese is one of the hardest languages to learn, only surpassed by Chinese. On the other hand, it's not as impossible as people make it out to be.

If you're taking decent university-level courses, you can learn enough Japanese in two years to be able to at least survive a study abroad year in Japan without much trouble. I know this because it's exactly what I did - two years of Japanese at my home uni, then I studied in Nagoya for a year. If you're aiming for fluency, this would be closer to four, maybe five years of study depending on the intensity of your courses.